Cooling unit and refrigeration assembly

ABSTRACT

An individual, customized individual cooling unit operably retainable to (i) a metallic container for holding chemicals, such as polyols/blowing agent mixture for use in the production of polyurethane foam to be cooled, wherein the container has an outer surface, and (ii) a refrigerator. The cooling unit has
         (a) a metallic thermal conductor having a first surface contractable with the container adjacent the container outer surface; and a second surface;   (b) a thermal insulation layer adjacent the second surface;   (c) coolant first conduit between the outer surface of the container and the thermal insulation layer, and having a coolant first inlet and a coolant first outlet; and   (d) a retainer for retaining the cooling unit to the container outer surface. The cooling unit and the refrigerator provide for the storage of the chemical at a safe temperature in a convenient, clean manner, with minimum energy usage in temperature control.

This application claims priority to U.S. appl'n. Ser. No. 60/882,953, filed 31 Dec. 2006, the complete disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a refrigeration assembly for cooling a chemical container, particularly in cooling stored polyols and blowing agent ingredients used in the production of polyurethane foam used for insulation, and to a cooling unit of use in said assembly.

BACKGROUND OF THE INVENTION

Polyurethane form insulation of use in interwall cavities of buildings and in other duties is generally produced on-site, by the in situ mixing of the major isocyanate and polyols ingredients having blowing agents to produce the polymeric foam, which subsequently hardens.

Typically, the isocyanate and polyol/blowing agent ingredients are each provided in separate standard 55 gallon metallic drums (500 lbs chemical), which are metered through a proportionator in generally a 1:1 to 2:1 isocyanate:polyols ratio, mixed and fed through a nozzle to the cavity, at a temperature of about 105° F. However, if the ambient temperature surrounding the drums, most particularly, the polyol/blowing agent drum, is high enough to cause the contents of the drum to reach about 26-28° C., the blowing agent expands to such a degree as to cause the drum to billow outwards under the gaseous pressure and cause the drum to explode. This is a most dangerous problem.

To-date, this problem has been addressed, in one manner, by covering the drum with a cooling, but messy wet, horse blanket, which also involves the inconvenience of the need for constant water dousing.

An alternative solution is to store the drums in an air conditioned environment, which involves wasteful, significant power usage, since vast volumes of space are, inevitably also cooled, particularly, when the drums are present and/or stored on-site in a truck or like vehicle where the chemical ingredients are to be mixed under the direction of manual operators, and truck doors and rear ends are, constantly, if not always maintained, open during foaming operations.

There is, therefore, a need for a method or system of storing the drums at a safe temperature, in a convenient manner, that minimize temperature-controlled energy usage.

The present invention provides such a solution that satisfies these criteria by, in effect, providing customized, individual cooling units, assembly and system.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a cooling unit, assembly and apparatus for cooling and maintaining the temperature of drum-stored chemicals, particularly, polyols/blowing agent mixtures for use in the on-site production of polyurethane foam.

Accordingly, in one aspect, the invention provides a cooling unit operably retainable to (i) a metallic container for holding chemicals to be cooled and having a container outer surface, and (ii) refrigeration means; said unit comprising

-   -   (a) a metallic thermal conductor having a first surface         contactable with said container adjacent said container outer         surface; and a second surface     -   (b) a thermal insulation layer adjacent said second surface;     -   (c) coolant first conduit means between said outer surface of         said container and said thermal insulation layer, and having         coolant first inlet means and coolant first outlet means; and     -   (d) retaining means for retaining said unit to said container         outer surface.

Typically, the container is a 55 gallon iron drum, around which the cooling unit, preferably, in the form of an arc is retained against 20% to 50% of the drum's surface.

The coolant conduit means is between said conductor first surface and said second surface.

The metallic conductor is preferably a plate formed of an iron, copper, aluminum or an alloy thereof, which is preferably held by magnets to the drum.

The coolant conduit in a preferred embodiment runs essentially within the metallic plate while having a cooling inlet and outlet at the ends of the plate.

The unit insulation layer can, for example, comprise polyurethane foam, fiber glass and/or thermoplastic bubblepack material.

External coolant input and output leads openly communicate the unit as hereinabove defined with a refrigerator having a temperature probe and which provides liquid coolant, e.g. a Freon coolant and receives gaseous spent coolant from the unit, for compression recycling.

Accordingly, in a further aspect, the invention provides a cooling assembly for cooling chemicals held in a container comprising a cooling unit and a refrigeration means in communication with said coolant first conduit means.

In a further aspect, the invention provides an assembly of such dimensions and weight, as to be manually portable.

Thus, the invention provides an individual cooling system, in effect, customized for use with standard drums. However, the invention further provides a cooling assembly wherein the refrigerator may have a plurality of coolant conduit connections, leads and the like to supply and receive spent fresh coolant to a plurality of drums, simultaneously.

The refrigerator may be powered by electric power supplied by a suitable power source, such as a battery, local utility supply of a building, truck or the like.

Thus, in a further aspect, the invention provides an apparatus comprising an assembly and a metallic container containing chemicals, as hereinabove defined, said container having a container outer surface, and wherein said retaining means retains said cooling unit to said container outer surface.

Preferably, the drum has a thermal insulation covering during storage.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be better understood, preferred embodiments will now be described, by way of example only, with reference to the accompanying drawings, wherein

(a) FIG. 1 is a diagrammatic perspective view of a cooling unit according to the invention;

(b) FIG. 2 is a diagrammatic cross-sectional view of a width on the line 2-2′ of the cooling unit shown in FIG. 1, affixed to a drum;

(c) FIG. 3 is a diagrammatic perspective view of a cooling assembly according to the invention affixed to a drum;

(d) FIG. 4 is a diagrammatic perspective view of the cooling assembly of FIG. 3 with the drum having an insulation cover;

(e) FIG. 5 is a diagrammatic perspective view of a refrigeration unit, according to the prior art, with major inner components in view;

(f) FIG. 6 is the cooling assembly shown in FIG. 3 modified to receive a plurality of coolant leads; and

(g) wherein the same numerals denote like parts.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows generally as 10, an arcuate-shaped aluminum belt-plate 12 of about 3 mm thickness, 20 cm height and 1 m curved length of a shape to intimately, partially follow the outer circumferential surface 14 of drum 16. A plurality (four) of magnets (4 cm) 18 extend from the inner surface 20 of plate 12 and by which magnets unit 10 is affixed to drum surface 14. Outer surface 22 of plate 12 is covered with a 10 cm thick polyurethane foam insulation layer 24.

Plate 12 has an inner conduit coolant network 26 between surfaces 20 and 22 having a fresh liquid coolant inlet 28 and spent gaseous coolant outlet 30, and through which network 26 refrigerant passes.

Coolant inlet 28 and outlet 30 are each connected to respective copper (1.5 mm ID) conduits within lead 32 for communication with a coolant supply and receiver refrigeration unit 34. Receiver 34 has a typical 1/12 HP compressor 36, condensing coil 38 and associated conduits 40 within housing 42. Power is supplied to refrigeration unit 34 by electrical lead 44 from an electrical source (not shown). A temperature probe 46 (AQUASTAT™ gas bulb thermometer) is connected to refrigeration unit 34.

To enhance thermal insulation and electrical efficiency, the assembly may have an insulation layer, for example, a metallic reflective bubble pack covering 48.

A single refrigeration unit 34 may be suitably modified to receive a plurality of leads 32 from individual cooling packs 10 being used, simultaneously, with a plurality of individual drums 14.

A refrigeration temperature controller 50 (T4031A,B,P-Honeywell) is suitable for temperature control.

The dimensions of each of cooling pack 10 and refrigeration unit 34 also provide ease of manual transportation. A typical size of unit 34 enables it to be carried in a 40 cm×40 cm×25 cm carry case.

While a typical 24,000 BTU air conditioning unit, typically located in a truck used to maintain a 55 gallon drum of polyol/blowing agent at a temperature of between 15°-25° C. consumes about 3,800 watts, an individual cooling pack and assembly of use in the present invention consumes between 300-400 watts.

An example of a typical polyol/blowing agent blended starting ingredient contains 60-70% w/w polyols, 7-13% w/w 1,1,1,3,3-pentafluoropropane, 7-13% w/w tris-iso-chloropropyl phosphate, 1-5% w/w tertiary amine blend, with the balance being inert additives. An example of a typical aromatic isocyanate starting chemical example is 4,4′-diphenyl methane diisocyanate. A mixing ratio of 1:1 at a mixing temperature of 40° C. is used.

Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to those particular embodiments. Rather, the invention includes all embodiments which are functional or mechanical equivalence of the specific embodiments and features that have been described and illustrated. 

1. A cooling unit operably retainable to (i) a metallic container for holding chemicals to be cooled and having a container outer surface, and (ii) refrigeration means; said unit comprising (a) a metallic thermal conductor having a first surface contactable with said container adjacent said container outer surface; and a second surface (b) a thermal insulation layer adjacent said second surface; (c) coolant first conduit means between said outer surface of said container and said thermal insulation layer, and having coolant first inlet means and coolant first outlet means; and (d) retaining means for retaining said unit to said container outer surface.
 2. A unit as claimed in claim 1 wherein said coolant conduit means is within said thermal conductor between said conductor first surface and said second surface.
 3. A unit as claimed in claim 1 wherein said container is a right-vertical cylinder and said first surface is arcuate and is intimately abutable with said container outer surface.
 4. A unit as claimed in claim 3 wherein said arcuate surface extends between 20%-50% around the circumference of said container outer surface.
 5. A unit as claimed in claim 1 wherein said retaining means comprises magnetic means retained to said unit.
 6. A unit as claimed in claim 1 wherein said thermal insulation layer is selected from polyurethane foam, fiber glass and thermoplastic bubblepack material.
 7. A unit as claimed in claim 1 wherein said thermal conductor is formed of a metal selected from iron, copper, aluminum and alloys thereof.
 8. A unit as claimed in claim 1 further comprising coolant second conduit means comprising (i) coolant second inlet means in communication with said first inlet means, (ii) coolant second outlet means in communication with said first outlet means, (iii) refrigerant receiving means and refrigerant retaining means.
 9. A cooling assembly for cooling chemicals held in a container comprising a cooling unit as claimed in claim 1 and a refrigeration means in communication with said coolant first conduit means.
 10. An assembly as claimed in claim 9 wherein said unit further comprises coolant second conduit means comprising (i) coolant second inlet means in communication with said first inlet means, (ii) coolant second outlet means in communication with said first outlet means, (iii) refrigeration receiving means and refrigeration retaining means and said refrigeration means comprises connection means; in communication with said refrigerant receiving means and refrigerant returning means of said unit.
 12. An assembly as claimed in claim 10 comprising a plurality of said connection means.
 13. An assembly as claimed in claim 9 further comprising temperature probe means for determining the temperature of said chemicals.
 14. An assembly as claimed in claim 9 having dimensions and weight as to be manually portable.
 15. Apparatus comprising an assembly as claimed in claim 9 and a metallic container containing chemicals, said container having a container outer surface, and wherein said retaining means retains said cooling unit to said container outer surface.
 16. Apparatus as claimed in claim 15 further comprising an insulation covering on said metallic container. 